Tools used (or similiar):
Headset press: tidd.ly/e6b950ff
Shop hammer: tidd.ly/57f45d00
Bearings for the Acros Ai-70 Fiber:
Upper: 6707-2RS, Inner x Outer x Depth (mm): 35 x 44 x 5
Bottom: AC3748, Inner x Outer x Depth (mm): 37 x 48 x 7 with one 45° chamfer on inner side
www.kineticbik...
Upper bearing on its own is available from:
www.airevelobea...
---------------------------------
The headset on my Canyon Endurace CF 9.0 Di2 2017 model lasted only 8 weeks or 800 miles from getting the bike brand new. The weather has been wet but it is disappointing.
The headset on this bike and many Canyons is made by Acros and is the Ai70. The top bearing is cheap and has good availability for under £10, but the lower bearing is only available from the headset manufacturer, and is ridiculously expensive. I phoned around and the cheapest I could find the bearings, which are sold as a pair, was £60. No third parties currently make the lower bearing but hopefully that will change. I will provide a link in the description if I do find a cheaper alternative.
In this case Canyon did send me the replacement headset bearings free of charge.
To make it easier to get the handlebars out of the way, remove the brake cable from the brake caliper.
Then loosen the stem bolts, and remove the cap. Take the handlebars off and attach to the frame using the foam packers that come with the bike if you still have them.
Keep an eye on the forks - they may drop out once you remove the stem.
Holding the forks remove them from the head tube and put them to one side.
In my case both bearings are rough, but the top bearing is worse. Whilst waiting for the new bearings to arrive I did try regreasing the top bearing, first removing the seal with a sharp object, using degreaser to wash away the existing grease and then using my grease gun to force as much grease back in as I could. There was a small improvement but I would only recommend it if you do it before the bearing has gone.
If your bottom bearing is ok, I have found the the top bearing for only £6.50 - link in the description.
The integrated bearings are press fitted so need tapping out. I used a drift and a hammer, but a screw driver would also do the job.
The top bearing comes out with a few taps. But the bottom bearing is tougher to remove.
I found the easiest way to punch out the bottom bearing, was to support the headtube with my left hand, feeling with my finger on the same hand the drift against the inside edge of the bearing. And then lightly tapping with a hammer, moving the drift around the bearing until it comes out.
The bottom bearing has a 45 degree chamfer on the bottom inside edge, that sits against the forks. So take note of that when you replace it.
Give the headtube a good clean with some degreaser and paper towel.
Lightly grease the top and bottom bearings and the headtube. Push fit them evenly as far as you can. Remember that the bottom bearing has the chamfer on inside facing the forks.
I used a headset press to insert them fully but you could use a drift, making sure to apply force to both the inside and outside race of the bearing evenly.
I found it easiest to use the old bearings as drifts to insert the new bearings, but with the bottom bearing be careful since the bearing is recessed a few mm and you don’t want to get the old bearing stuck in there too. I just started it off with the old bearing and then switched to my headset press only to lightly finish off.
Smear some grease on the forks at the crown, and a little over the top bearing. I also gave the clamp assembly that adjusts the play in the headset a clean before reassembling. Make sure to loosen the torx screw before assembly.
Final assembly needs to be done off the back stand. Loosen the stem bolts again, and make sure the forks are fully seated.
Ensure everything is straight, and that the cap is inserted before tightening to 5Nm with a torque wrench if you have one. Then take out any play by tightening the torx screw on the clamp. Check for play by applying the front brake and feeling with your fingers between the top of the headtube and the Acros clamp - there shouldn’t be any movement as you push back and forth on the bike.
15 окт 2024
